In the 1970s, the federal government instituted the word "Hispanic" to get a better handle on a mushrooming demographic group that was multiracial and multiethnic. In spite of criticism, that label stuck.

Now the U.S. Census Bureau is proposing a potentially more controversial change: to collapse two questions on race and ethnicity into one, creating a "Hispanic race" category. Congress won't decide it until 2018, when the wording of the 2020 census is approved. But Latino advocacy groups, scholars and others are criticizing the category as inaccurate, inadequate and ludicrous.

"The challenge is many Latinos understand themselves in racial terms instead of as an ethnic group," said Louis DeSipio, a professor of political science and Chicano studies at UC Irvine. "The Census Bureau is looking for simplification, which is appropriate, but ... has proposed to come up with a single question that forces respondents to think of themselves as a racial term, which some may not be comfortable with."

The proposed changes are part of the Census Bureau's 2010 Alternative Questionnaire Experiment Report, in which a half-million households received varying questions to see how the responses differed.

The results prompted several recommended changes, including the elimination of the word "Negro" in its race question, a proposal many regard as long overdue.

Clear or confusing?

The change would replace one confusing approach with another, DeSipio said. While the combined question may be simpler, it's a change that will require strong outreach to Latino communities to make sure it's understood.

An accurate count of the Hispanic population is especially vital in California, where Hispanic residents are poised to outnumber non-Hispanic white people by 2014. Only one other state, New Mexico, has more Hispanics than any other individual group.

Preliminary results already show an increase in responses, which have lagged among Hispanics.

In the 2010 census, more than half of Hispanics identified themselves as "white." Thirty-seven percent answered "some other race."

"That's how you know there's a problem," said Professor Jorge Chapa of the University of Illinois at Urbana-Champaign. "The data on race is not very good when 37 percent say essentially 'none of the above.' "

In California, where most Hispanic residents are of Mexican origin, the new process could feel more intuitive than in states with Latino racial groups that mainly identify as white.

"Some would be more comfortable - I get the sense that Mexican Americans couldn't care less either way - whereas Cuban Americans might be more sensitive around an identification that might minimize whiteness," DeSipio said.

Matter of perspective

People have reacted emotionally to the proposed change. "That's important," Chapa said, but they need to see the broader view.

Since 2000, people have been able to mark one or more race, but only one Hispanic ethnicity.

While the latter is an easier question (except perhaps for those who are, say, half-Mexican American and half-Puerto Rican), Chapa said the race question has confused some respondents.

Some Latinos don't regard themselves as white, black or any of the other choices. Some might identify as mestizo, a mix of European and indigenous, but that does not appear on the census form.

"That's their genetic heritage," Chapa said, speaking specifically of Mexican Americans. "They're European white as well as Native American or Indian. There's Asian and African heritage mixed there, too."

Asking about race poses other issues.

"The way (Latinos) identify their race definitely is not what others would identify them as," Chapa said. "People in the same family might self-identify differently and may look different."

In spite of such issues, the prospect of getting better information makes a "Hispanic race" category in the 2020 census a good idea, he said.

Could it hurt?

In an essay for the National Institute for Latino Policy, she said a "Hispanic race" question would result in less-detailed ethnic data, which would hurt the monitoring of discrimination in housing, jobs, political participation, education, health and criminal justice.

"If we collapse race and ethnicity as interchangeable concepts, we may miss the opportunity to examine whether there are unique experiences among co-ethnics that may occupy very different racial statuses," she said. "It will be challenging to capture the two concepts with one question."

Offensive to some

Any change on race in census forms will be problematic, said Angelo Falcon, president of the National Institute for Latino Policy and head of a former census committee on Hispanics.

"Some (Latinos) find it offensive to ask about race," he said.

Falcon, who has not decided whether to support the "Hispanic race" question, said the Census Bureau has held more than 60 focus groups in the past couple of years to get feedback on proposed changes.

"One of the things they seemed to find is by combining the two questions, you get a better response rate," he said. "It was clearer to people and more inclusive."

For Falcon and others, what's crucial is Latino involvement.

"The census is a big event for us every 10 years," he said. "Meanwhile, these guys are making all kinds of decisions for us. We have to be part of the discussion, because it's so critical to the work we do in the community, in civil rights, redistricting, health care and in, apparently, reintroducing us to America every 10 years.

"This is just the beginning of a very long conversation."

Recommended census changes

Combined question: Further test a combined race and Hispanic-origin question to increase reporting.

Multiple responses: If the Hispanic-origin question is kept separate, allow multiple responses by explicitly including the "mark one or more" instruction, giving respondents the option to report their full self-identified origin.

Dropping term: Remove the term "Negro" from the "Black, African American or Negro" response category.

Elaine Ayala is a reporter for the San Antonio Express-News. Ellen Huet is a San Francisco Chronicle staff writer. E-mail: ehuet@sfchronicle.com Twitter: @ellenhuet